AMR dissemination in the environment Professor Liz Wellington

Transcription

1 AMR dissemination in the environment Professor Liz Wellington

2 The connectivity of potential sources of antibioticresistant bacteria

3 Antibiotic resistance in the environment: soil, sediments, water bodies Environment acts as an reservoir for antibiotic resistance genes: -associated with antibiotic biosynthesis clusters - in closely related non-producers - in unrelated non-producers indigenous soil bacteria - in unrelated non-producers exotic bacteria = pathogens/commensals added to soil Potential for selection of resistance -pollution HGT of resistance genes- mobilome Pathogens can survive in soil -Acquire integrons/plasmids -Act as source of antibiotic resistance

4 Non-producers Tetracycline Non-producers Gentamicin Producers Streptomycin Non-producers Streptomycin Reservoirs of antibiotic resistance genes in diverse environments: survey Soil Rhizosphere Manure Sewage Seawater Prevalence aph3 aph6-id ant3 adenylase aph6-ic aph6-ic (deg) stra aphd strb1 stsc aac(3)-i aac(3)-ii/vi aac(3)-iii/iv aac(6 )-II/Ib ant(2 )-I aph(2 )-I teta tetb tetc tetd tete tetg teth tetk tetl tetm teto tett Soil Rhizosphere Manure Sewage Seawater

5 Substitution rate Streptomycin biosynthetic cluster and mobility of resistance gene stra in soil Substitution rate in housekeeper genes vs. streptomycin resistance stra (APH II) Laskaris et al., Env Micro 12,

6 The connectivity of potential sources of antibioticresistant bacteria

7 Sewage treatment and disposal Application of sewage sludge /biosolids/ manure to land: what is the impact on antibiotic resistance in soil?

8 Antibiotic class Occurrence of antibiotics in the natural environment, fish, crops and drinking water from published studies General behaviour Chloramphenicol impersistent/ 2,4- diaminopyridines mobile persistent/ Sewage sludge River water Groundwat er Drinking water Fish Soil Crops Example compounds monitored - X immobile X X - trimethoprim Fluoroquinolones persistent/ immobile X X - - ciprofloxacin, norfloxacin, ofloxacin -lactams impersistent mobile - X X X amoxicillin, cloxacillin, dicloxacillin, methicillin, nafcillin, oxacillin, penicillin G, penicillin V Macrolides slightly persistent/ slightly mobile X azithromycin, clarithromycin, lincomycin, roxithromycin, spyramycin, tylosin Sulfonamides persistent/ mobile X - sulfamethoxazole, sulfadiazine, sulfamerazine, sulfamethazine, sulfapyridine Tetracyclines persistent/ immobile - X X chlortetracycline, doxycycline, oxytetracycline, tetracycline A tick means that it has been monitored for and detected and a cross means that it has been monitored for and not detected. No entry means that no monitoring has been done yet (Alistair Boxall)

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10 Schematic map of the complex class 1 integron carrying the bla CTX-M-14 gene on plasmid paje0508 gene on plasmid paje0508 Bae et al., AAC, Aug 2007,

11 Class 1 integron prevalence in sewage sludge, pig slurry and following application to land RB, Reed bed sediment from textile mill; SS, Fully digested sewage sludge; PS, Pig slurry; CW, Fallowed agricultural soil + Pig slurry prevalence (%) inti1 qace 1 qace qacg qach prevalence % inti RB SS PS CW sample site preapplication day 1 day 21 day 90 day 289 days after slurry application 90 million tons animal faecal slurry added to UK soils per year Gaze et al., 2011 ISME J ; Bailey-Byrne et al 2011 AEM

12 Low cost AMR carriage gives selection with very low exposure Gulleberg et al., 2014 mbio

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14 Waste water treatment plants as a reservoir for antibiotic resistance Waste Water treatment plants Hotspot for Horizontal Gene Transfer (HGT) as waste received from various sources Little is known about the impacts of effluent further downstream in the river or the possible role of co-selection of antibiotic resistant determinants via quaternary ammonium compounds (QACs) (Gaze et al., AAC 2005, ISMEJ 2011)

15 The risk of consuming 3GC resistant coliforms equal to or greater than the dose needed for colonization can be calculated using the inverse cumulative Poisson distribution P = 1 e λ k i=100 P= probability of being colonized by a 3GC resistant coliform. λ = average number of 3GC coliforms consumed, which is equal to number of 3GC coliforms multipled by the amount of water consumed (ml). i = 100, the number of coliforms needed for colonization. The volume of water consumed for > 99% probability of transient colonization of a 3GC resistant coliform at minimum levels of sediment disturbance was 12 5 ml downstream and 58 ml upstream, and under high levels of sediment disturbance, will decrease to 1 3 ml downstream and 5 8 ml upstream. Children swimming (37 ml of water consumed on average) downstream of treatment plants have a P > 99 % chance of being transiently colonized by a 3GC resistant coliform. Upstream of the WWTP, even under high levels of sediment disturbance, only swimming carried risks of colonization by 3GC resistant coliforms. λ i i!

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19 Contribution of WWTP effluent to integron levels in a whole river system River Thames catchment area: Collaboration with Wallingford CEH, meta-data available 13 sites samples every 3 months for a year: analysed for integron prevalence and 3GC resistance counts

20 Integron Prevalence / (%) Integron prevalence Significant difference between summer months (May and August, and Winter months November and February P = t-test May August February November Sample site

21 Actual log integron prevalence actual log integron prevalence Output WWTP only All metadata included Predicted log integron prevalence Explained 49 % of variance: R 2 adjusted (0.49) P < Predicted log integron prevalence Explained % of variance : R 2 adj (0.83) P < 0.01 Amos et al., 2015 ISME J

22 New sampling campaign Thames Catchment

23 New Campaign Small scale intensive sampling, planktonic, sediment, direct and indirect WWTPs, Monitoring stations and fishfarms

24 Acknowledgements Past: William Gaze Greg Amos Lihong Zhang Kathy Byrn-Bailey Paris Laskaris Leo Calvo-Bado Helen Green Present: Gemma Hill Hayley King Jennie Holden Severine Rangama Chiara Borsetto University of Birmingham Professor Peter Hawkey Claire Murray Katie Hardy Rothamsted Research Andrew Mead CEH Wallingford Andrew Singer